Street Design Manual

shoulder, or other transition, and bioswales, which can take the place of traditional curb and gutter in some applications. Permeable pavement also can be appropriate for use in the shoulder. F. Median - Medians can range in width depending on street type and context. They may accommodate integrated turn lanes, pedestrian refuges at cross-streets and mid-block, drainage swales, shade trees, promenades, transit lines and stations. If space permits, landscaped medians provide a beneficial aesthetic and street narrowing effect in almost any context. Medians are conducive to the use of GSI elements that can offer several benefits. Depressed medians can be designed as bioretention islands or vegetated/bioswales that incorporate curb cuts to allow runoff to pass from gutters or other conveyance to these depressions. Alternatively, rock swales can be incorporated in medians where growth and/or maintenance of vegetation may be difficult. Permeable pavement also can be installed in medians as an alternative to conventional, impervious pavement, where the use of vegetation is not suitable. G. Turn Lane - Turn lanes may be continuous, integrated with spot medians, or installed at intersections with high vehicular turning volume. Where center left turn lanes are provided on streets with four or more general travel lanes, medians with a pedestrian refuge shall be added to aid in safe crossing as well as more efficient traffic signal phasing. Article 2.3 Roadway Classification Design Vehicle Type The Design Vehicle Table lays out the vehicle types have been used in the engineering specifications for each street type. Every street type shall appropriately accommodate emergency vehicles. . Table 1 Design Vehicle Table Street Type Design Vehicle

Single Unit Truck (SU-30) Interstate Semi-Trailer (WB-62)

Sensitive Area Street

Passenger Car (P) Single Unit Truck (SU-30) Single Unit Truck (SU-30)

Local Streets

Mixed Use Streets

Intermediate Semi-Trailer (WB-40) Interstate Semi-Trailer (WB-62) Interstate Semi-Trailer (WB-62) Single Unit Truck (SU-30), Person

Major Streets

Industrial and Service Streets

Accessways

Alley

Single Unit Truck (SU-30)

Raleigh Street Design Manual – Page 5